Tissue reconstruction and closure of incisions or wounds is pertinent to almost all surgical interventions and traumatic injuries. Tissue sealants and hemostatic agents are sometimes utilized for preventing excess blood loss during surgical procedures. Current commercially available tissue sealants are composed of fibrin, glutaraldehyde, or synthetic hydrogel based materials. Fibrin sealants have relatively poor mechanical properties, and are relatively high in cost and complex to prepare for application. In addition, fibrin sealants pose a relatively high risk of disease transmission (Spotnitz W. D. & Burks S. (2012) “Hemostats, sealants, and adhesives III: a new update as well as cost and regulatory considerations for components of the surgical toolbox,” Transfusion 52(10):2243-55). Glutaraldehyde-protein sealants are lower in cost as compared to fibrin sealants, but suffer from toxicity issues which severely restrict their clinical potential (Furst W. & Banerjee A (2005) “Release of glutaraldehyde from an albumin-glutaraldehyde tissue adhesive causes significant in vitro and in vivo toxicity,” Annals of Thoracic Surgery 79(5):1522-9). Some conventional hydrogel sealants are non-cytotoxic and exhibit a lower risk of disease transmission as compared to fibrin sealants, but require complicated multi-step preparation and are prone to excessive swelling after use. Such swelling can cause injury to neighboring anatomic structures such as nerves or even the tissue involved (Spotnitz W. D. & Burks S. (2008) “Hemostats, sealants, and adhesives: components of the surgical toolbox,” Transfusion 48(7):1502-16). As a result of the problems and deficiencies associated with commerically available sealants, conventional suturing and tissue stapling remain ubiquitous to many procedures despite exhibiting limited capability, and few advances have been made with regard to improving these conventional techniques.
Polymer mats and scaffolds have been utilized for wound dressings (Khil M. S. et al. (2003) “Electrospun nanofibrous polyurethane membrane as wound dressing,” J. Biomed. Mater. Res. B. 67B(2):675-9), and in various other biomedical applications including drug delivery (Jing Z. et al. (2003) “Biodegradable electrospun fibers for drug delivery,” J. Control Release 92(3):227-231), tissue engineering (Li W. J. et al. (2002) “Electrospun nanofibrous structure: A novel scaffold for tissue engineering,” J. Biomed. Mater. Res. 60(4):613-621), and enzyme immobilization (Wang Z. G. et al. (2009) “Enzyme immobilization on electrospun polymer nanofibers: An overview,” J. Mol. Catal. B-Enzym. 56(4):189-95). Nanofibers are typically generated by electrospinning, a process that utilizes an electric field applied to a drop of polymer melt or solution on the tip of a nozzle (Agarwal S. et al. (2008) “Use of electrospinning technique for biomedical applications,” Polymer 49(26):5603-21). The droplet deforms forming a Taylor cone and a charged jet accelerates toward the target generating nanofibers (Yarin A. L. (2001) “Taylor cone and jetting from liquid droplets in electrospinning of nanofibers,” J. Appl. Phys. 90(9):4836-46). Electrospinning requires specialized equipment, high voltages, electrically conductive targets, and suffers from a relatively low deposition rate. As such, the use of electrospinning for the direct deposition of fibers in surgical applications has not been permissible.
Accordingly, there is a need for an effective tissue sealant that is relatively inexpensive to fabricate, that may be readily deposited on any surface in situ, and that exhibits a relatively low risk of inflammatory response and disease transmission as compared to currently available sealants. There is also a need for improved methods of fabricating polymer fibers. The present invention is directed to compositions and methods that overcome some or all of the deficiencies associated with conventional sealant materials, devices and fabrication methods.